The present invention relates to devices for endoscopic examination which are movable in a body cavity in a predetermined direction without pushing from outside, for example in intestine and can carry equipment that are necessary for diagnostics and treatment of the intestine. It also relates to a method of moving such devices in a body cavity.
There are many devices of this type; however they are not used in practice. Medical personnel move medical instruments and diagnostic equipment into intestine manually. Taking into consideration that the intestine has a complicated shape and length about 1.5 meter it is quite a difficult problem for the medical personnel. During this process, the intestine is subjected to significant deformations which cause pain to a patient and sometimes perforations of an intestine wall. The above mentioned deformations are caused, because along the whole length of the intestine the direction of a force which moves the device and the direction of its movement do not coincide with one another.
The devices disclosed in the patents are designed to solve this problem, so that the devices are moved in a self-moving manner and carry the equipment which is necessary for diagnostics and treatment. When the device is introduced into an intestine, it moves further under the action of a force applied to its front part relative to the wall of the intestine and directed along the intestine. The movement is carried out by small steps, and within each of the steps the direction of movement coincides with the direction of the applied force. As a result, the deformations of the intestine should be minimal. However, in order to apply the force relative to the wall of the intestine, it is necessary to provide a point of support. This poses the major problem since the walls of the intestine are very slippery, thin and elastic in a transverse direction. In the known devices the corresponding elements formed as legs, prongs, balloons, etc., still cause deformation of the intestine from inside when these elements try to engage the walls of the intestine.
U.S. Pat. No. 5,906,591 to Dario, et al discloses an endoscopic robot which, for its movement, provides points of support by means of vacuum attaching elements formed as two perforated cylinders located one behind the other. The attaching elements formed in this way are not efficient, since the openings in them are very small. In addition they are arranged over the whole surface of the cylinders, so that generation of a vacuum is not guaranteed. It sufficies to have one opening which does not touch the wall of the intestine, and the vacuum in the corresponding attaching element disappears. If level of vacuum is increased in order to improve efficiency, the walls of the intestine can be damaged. Also, the negative factor from the point of view of safety of intestine walls is that during the movement the attaching elements formed in this way pass the same point twice, by the front attaching element and then by the rear attaching element. Also, it is difficult to connect additional diagnostic or treatment elements to the device disclosed in this reference.
Another device of this type—is disclosed for example in a U.S. published patent application. This application discloses a device in which there are two attaching elements which are aligned with one another and are displaced by small steps consecutively one after the other over the same path in a longitudinal direction and alternatingly attached to a wall of the intestine under the action of vacuum and pressure. While this device can be considered an improvement, the disadvantage of this device is the particular trajectory of movement, in accordance with which the two attaching elements move one after the other over the same line. When one of the attaching elements is detached from the wall of the intestine the intestine is immediately deformed back, which causes the corresponding problems. It is believed that the existing devices can be further improved.